| 摘要 |
PURPOSE:To improve perfection, stabilization and durability in the combustion by specifying the structure of exhaust passage, exhaust branch pipe part and branch pipes concentrating part. CONSTITUTION:In concurrence of respectively making contiguous arrangements of exhaust ports 2, 4 of first, second exhaust conduits 1, 3 and exhaust ports 5, 7 of third, fourlth exhaust conduits which are unified their exhaust passages 9, 9 at the downstream with casting up together dual inner pipes 12 composed of inner, outer pipes 12', 12'' with poor heat conduction made of stainless steel or the like interposed air layers 10, 11 in the exhaust passage 9, branch pipe parts 21, 21 and branch pipes concentrating part 22 corresponding to the exhaust passage 9 are constituted by a split type inner pipe 23 composed of at least dual upper side materials 25', 25'' and lower side materials 26', 26'' with poor heat conduction made of stainless steel of the like having spatial layers 30, 31 at the outer bulkhead and each back side. This facilitates high retention temperature on the whole exhaust passage to lead from exhaust ports 2, 4, 6, 8 in a main chambert 17 to the branch pipes concentrating part 22, at the same time as mixed air made thinner than theoretic air-to-fuel ratio is entirely stabilized in the main chamber 17 before burning, unburned gas is made self-combustion and purified, to attain the desired purpose. |
